1. Field of the Invention
This invention relates to cleaning and sanitizing compositions which contain n-alkyl and/or n-alkenyl succinic acids as the active antimicrobial agent.
2. Background of the Prior Art
Various chemicals exhibit varying degrees of antimicrobial activity. Among these are short-chain monocarboxylic acids having less than twenty carbon atoms, quaternary ammonium compounds and hexachlorophene compounds. These compounds have been admixed with various surfactants and water to yield aqueous sanitizing solutions.
It has been found that the antimicrobial activity of these compounds can be incresed when the sanitizer solution is acidified to a pH below about 5. Acid sanitizing solutions of this type are generally employed in food, beverage, brewery and other industries as a clean-in-place, sanitizing solution for processing equipment.
Generally, antimicrobial solutions containing these antimicrobial agents are undesirable for use in food equipment cleaning applications. Residual amounts of the acid sanitizing solutions which remain in the equipment after cleaning can impart unpleasant tastes and odors to food. The cleaning solutions are difficult to rinse from the cleaned surfaces. Larger amounts of water are required to effectively completely remove conventional sanitizing solutions. Those sanitizers containing halogens can be corrosive to metal surfaces of food plants. Quaternary ammonium compounds strongly adhere to sanitized surfaces even after copious rinsing and may interfere with desired microbial growth during food processing; e.g. fermentation.
It has, also, been found that the antimicrobial activity of conventional acid sanitizing solutions can be adversely affected by the hardness of the water used in and with the solution. A marked decrease in antimicrobial activity has been noted at water hardness above about 500 ppm. Therefore, in order to assure sufficient antimicrobial activity, the hardness of water must be carefully adjusted to maintain the harness below about 500 ppm.
The acid sanitizing solutions presently available are effective against gram negative and gram positive bacteria such as E. coli. and Staph. aureaus but are not as efficacious on any yest contamination which can be present. In many applications control of yeast infestations requires a separate solution than that which is used to eliminate gram negative and gram positive bacteria. Use of two solutions can be costly and time consuming.
Thus, it is desirable to provide an antimicrobial solution which is equally effective on gram negative and gram positive bacteria and on yeast. It is also desirable that the antimicrobial activity of the solution be unaffected by water hardness.